Asian giant hornet
Encyclopedia
The Asian giant hornet including the subspecies Japanese giant hornet
(Vespa mandarinia japonica), colloquially known as the yak-killer hornet, is the world's largest hornet
, native to temperate and tropical Eastern Asia. Its body length is approximately 50 mm (2 in), its wingspan about 76 mm (3 in), and it has a 6 mm (0.236220472440945 in) sting
which injects a large amount of potent venom.
of the hornet is orange and quite wide in comparison to other hornet
species. The compound eyes and ocelli
are dark brown, and the antennae
are dark brown with orange scape
s. The clypeus
(the shield-like plate on the front of the head) is orange and coarsely punctured; the posterior side of the clypeus has narrow, rounded lobes. The mandible is large and orange with a black tooth (inner biting surface) which is used for burrowing.
The thorax
and propodeum
(the segment which forms the posterior part of the thorax) of the Asian giant hornet has a distinctive golden tint and a large scutellum (a shield-like scale on the thorax) that has a deeply-impressed medial line; the postscutellum (the plate behind the scutellum) bulges and overhangs the propodeum. The hornet's forelegs
are orange with dark brown tarsi
(the distal—furthest down—part of the leg); the midlegs and hindleg
s are dark brown. Wing
s are a dark brownish-gray. The tegula
e are brown.
The gaster
(the portion of the abdomen behind the thorax
–abdomen
connection) is dark brown with a white, powdery covering; with narrow yellow bands at the posterior margins of the tergite, the sixth segment is entirely yellow. It is similar in appearance to the established European hornet
, Vespa crabro.
It can be found in the Primorsky Krai
region of Russia, Korea
, China
, Taiwan
(where it is called 虎頭蜂; "tiger head bee"), Indochina
, Nepal
, India
, and Sri Lanka
, but is most common in rural areas of Japan
, where it is called .
that contains, like many bee and wasp venoms, a cytolytic
peptide
(specifically, a mastoparan
) that can damage tissue by stimulating phospholipase
action, in addition to its own intrinsic phospholipase. Masato Ono, an entomologist
at Tamagawa University
near Tokyo
, described the sensation as feeling "like a hot nail being driven into my leg."
An allergic human stung by the giant hornet may die from an allergic reaction
to the venom, but the venom contains a neurotoxin
called mandaratoxin (MDTX), a single-chain polypeptide with a molecular weight of approximately 20,000 u
, which can be lethal even to people who are not allergic if the dose is sufficient. Each year in Japan, the human death toll caused by Asian giant hornet stings exceeds that of all other venomous and non-venomous wild animals combined, including wild bears and venomous snakes.
s, such as bee
s, other hornet species, and mantis
es.
The hornets often attack honey bee
hives with the goal of obtaining the honey bee larva
e. A single scout, sometimes two or three, will cautiously approach the nest, giving off pheromones which will lead the other hornets to the hive's location.
The hornets can devastate a colony of honey bees: a single hornet can kill as many as 40 honey bees per minute thanks to its large mandibles which can quickly strike and decapitate a bee. It takes only a few of these hornets a few hours to exterminate the population of a 30,000-member hive, leaving a trail of severed insect heads and limbs. The European honey bee
s Apis mellifera have small stings which do little damage to hornets that are five times their size and twenty times their weight. The honey bees make futile solo attacks without mounting a collective defense, and are easily killed individually by the hornets. Once a hive is emptied of all defending bees, the hornets feed on the honey and carry the larvae back to feed to their own larvae. The hornets can fly up to 100 kilometres (62.1 mi) in a single day, at speeds of up to 40 kph
Adult hornets cannot digest solid protein, so the hornets do not eat their prey, but chew them into a paste and feed them to their larvae. The larvae produce a clear liquid, vespa amino acid mixture, which the adults consume; larvae of social Vespidae produce these secretions, the exact amino acid composition varying considerably among species. The passing of nutrition to adult wasps by larvae is widespread in these wasps, and not restricted to the genus Vespa
.
Although a handful of Asian giant hornets can easily defeat the defenses of many individual honey bees, whose small stings cannot inflict much damage against such a large predator, the Japanese honey bee (Apis cerana japonica
) possesses a collective defense against them.
When a hornet scout locates and approaches a Japanese honey bee hive it will emit specific pheromonal hunting signals. When the honey bees detect these pheromones, a hundred or so will gather near the entrance of the nest and set up a trap, keeping it open apparently to draw the hornet further into the hive or allow it to enter on its own. As the hornet enters the nest, a large mob of about five hundred honey bees surrounds it, completely covering it and preventing it from moving, and the bees begin to quickly vibrate their flight muscles. This has the effect of raising the temperature of the honey bee mass to 46 °C (114.8 °F). In addition, the mob of honey bees raises the level of carbon dioxide (CO2) around the hornet. At that concentration of CO2, the honey bees can tolerate up to 50 °C (122 °F), but the hornet cannot survive the combination of a temperature of 46 °C (114.8 °F) and high carbon dioxide level, so it dies. Often several bees perish along with the intruder, but the death of the hornet scout prevents it from summoning reinforcements which would wipe out the colony.
Beekeepers in Japan attempted to introduce the European honeybee in order to increase productivity. European honeybees, however, have no natural defense against the hornet and the colonies are rapidly destroyed.
s and energy drink
s which contain synthetic versions of secretions of the larvae of Vespa mandarinia, which the adult hornets usually consume. The manufacturers of these products make claims that consuming the larval hornet secretions (marketed as "hornet juice") will enhance human endurance because of the effect it has on adult hornets' performance. Because these products are marketed as dietary supplement rather than pharmaceuticals, they do not have to support their claims. Some studies have suggested that the vespa amino acid mixture itself may influence animal performance in minor ways.
Japanese giant hornet
The Japanese giant hornet , is a subspecies of the Asian giant hornet . It is a large insect and adults can be more than long, with a wingspan greater than . It has a large yellow head with large eyes, and a dark brown thorax with an abdomen banded in brown and yellow...
(Vespa mandarinia japonica), colloquially known as the yak-killer hornet, is the world's largest hornet
Hornet
Hornets are the largest eusocial wasps; some species can reach up to in length. The true hornets make up the genus Vespa and are distinguished from other vespines by the width of the vertex , which is proportionally larger in Vespa and by the anteriorly rounded gasters .- Life cycle :In...
, native to temperate and tropical Eastern Asia. Its body length is approximately 50 mm (2 in), its wingspan about 76 mm (3 in), and it has a 6 mm (0.236220472440945 in) sting
Stinger
-Biology:* Stinger, an organ or body part found in various animals that usually delivers some kind of venom.* Stinger , a minor neurological injury suffered by athletes.-Sports and entertainment:...
which injects a large amount of potent venom.
Anatomy
The headHead
In anatomy, the head of an animal is the rostral part that usually comprises the brain, eyes, ears, nose and mouth . Some very simple animals may not have a head, but many bilaterally symmetric forms do....
of the hornet is orange and quite wide in comparison to other hornet
Hornet
Hornets are the largest eusocial wasps; some species can reach up to in length. The true hornets make up the genus Vespa and are distinguished from other vespines by the width of the vertex , which is proportionally larger in Vespa and by the anteriorly rounded gasters .- Life cycle :In...
species. The compound eyes and ocelli
Ocellus
A simple eye refers to a type of eye design or optical arrangement that contains a single lens which detect light. A "simple eye" is so-called in distinction from a multi-lensed "compound eye", and is not necessarily at all simple in the usual sense of the word...
are dark brown, and the antennae
Antenna (biology)
Antennae in biology have historically been paired appendages used for sensing in arthropods. More recently, the term has also been applied to cilium structures present in most cell types of eukaryotes....
are dark brown with orange scape
Antenna (biology)
Antennae in biology have historically been paired appendages used for sensing in arthropods. More recently, the term has also been applied to cilium structures present in most cell types of eukaryotes....
s. The clypeus
Clypeus
The clypeus is one of the sclerites that makes up the "face" of an arthropod.In insects, the clypeus delimits the lower margin of the face, with the labrum articulated along the ventral margin of the clypeus. The mandibles bracket the labrum, but do not touch the clypeus. The dorsal margin of the...
(the shield-like plate on the front of the head) is orange and coarsely punctured; the posterior side of the clypeus has narrow, rounded lobes. The mandible is large and orange with a black tooth (inner biting surface) which is used for burrowing.
The thorax
Thorax (insect anatomy)
The thorax is the mid section of the insect body. It holds the head, legs, wings and abdomen. It is also called mesosoma in other arthropods....
and propodeum
Propodeum
The propodeum is the first abdominal segment in Apocrita Hymenoptera . It is fused with the thorax to form the mesosoma. It is a single large sclerite, not subdivided, and bears a pair of spiracles. It is strongly constricted posteriorly to form the articulation of the petiole, and gives apocritans...
(the segment which forms the posterior part of the thorax) of the Asian giant hornet has a distinctive golden tint and a large scutellum (a shield-like scale on the thorax) that has a deeply-impressed medial line; the postscutellum (the plate behind the scutellum) bulges and overhangs the propodeum. The hornet's forelegs
Forelimb
A forelimb is an anterior limb on an animal's body. When referring to quadrupeds , the term foreleg is often instead used....
are orange with dark brown tarsi
Arthropod leg
The arthropod leg is a form of jointed appendage of arthropods, usually used for walking. Many of the terms used for arthropod leg segments are of Latin origin, and may be confused with terms for bones: coxa , trochanter , femur, tibia, tarsus, ischium, metatarsus, carpus, dactylus ,...
(the distal—furthest down—part of the leg); the midlegs and hindleg
Hind limb
A hind limb is a posterior limb on an animal. When referring to quadrupeds, the term hind leg is often instead used....
s are dark brown. Wing
Insect wing
Insects are the only group of invertebrates known to have evolved flight. Insects possess some remarkable flight characteristics and abilities, still far superior to attempts by humans to replicate their capabilities. Even our understanding of the aerodynamics of flexible, flapping wings and how...
s are a dark brownish-gray. The tegula
Tegula (anatomy)
A tegula is a small sclerite situated above the base of the costal vein in the wings of various insects such as Lepidoptera, Hymenoptera, Diptera, and Homoptera, and attached to the antero-lateral portion of the mesonotum....
e are brown.
The gaster
Gaster
The gaster is the bulbous posterior portion of the metasoma found in Apocrita Hymenoptera . This begins with abdominal segment III on most ants, but some make a postpetiole out of segment III, in which case the gaster begins with abdominal segment IV....
(the portion of the abdomen behind the thorax
Thorax (insect anatomy)
The thorax is the mid section of the insect body. It holds the head, legs, wings and abdomen. It is also called mesosoma in other arthropods....
–abdomen
Abdomen
In vertebrates such as mammals the abdomen constitutes the part of the body between the thorax and pelvis. The region enclosed by the abdomen is termed the abdominal cavity...
connection) is dark brown with a white, powdery covering; with narrow yellow bands at the posterior margins of the tergite, the sixth segment is entirely yellow. It is similar in appearance to the established European hornet
European hornet
The European hornet Vespa crabro, commonly known simply as the "hornet", is the largest European eusocial wasp. The queen measures 25 to 50 mm long; males and workers are smaller...
, Vespa crabro.
Geographic distribution
Primorsky Krai
Primorsky Krai , informally known as Primorye , is a federal subject of Russia . Primorsky means "maritime" in Russian, hence the region is sometimes referred to as Maritime Province or Maritime Territory. Its administrative center is in the city of Vladivostok...
region of Russia, Korea
Korea
Korea ) is an East Asian geographic region that is currently divided into two separate sovereign states — North Korea and South Korea. Located on the Korean Peninsula, Korea is bordered by the People's Republic of China to the northwest, Russia to the northeast, and is separated from Japan to the...
, China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
, Taiwan
Taiwan
Taiwan , also known, especially in the past, as Formosa , is the largest island of the same-named island group of East Asia in the western Pacific Ocean and located off the southeastern coast of mainland China. The island forms over 99% of the current territory of the Republic of China following...
(where it is called 虎頭蜂; "tiger head bee"), Indochina
Indochina
The Indochinese peninsula, is a region in Southeast Asia. It lies roughly southwest of China, and east of India. The name has its origins in the French, Indochine, as a combination of the names of "China" and "India", and was adopted when French colonizers in Vietnam began expanding their territory...
, Nepal
Nepal
Nepal , officially the Federal Democratic Republic of Nepal, is a landlocked sovereign state located in South Asia. It is located in the Himalayas and bordered to the north by the People's Republic of China, and to the south, east, and west by the Republic of India...
, India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
, and Sri Lanka
Sri Lanka
Sri Lanka, officially the Democratic Socialist Republic of Sri Lanka is a country off the southern coast of the Indian subcontinent. Known until 1972 as Ceylon , Sri Lanka is an island surrounded by the Indian Ocean, the Gulf of Mannar and the Palk Strait, and lies in the vicinity of India and the...
, but is most common in rural areas of Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
, where it is called .
Sting
The sting of the Asian giant hornet is about 6(10) mm (¼ in) in length, and injects an especially potent venomVenom
Venom is the general term referring to any variety of toxins used by certain types of animals that inject it into their victims by the means of a bite or a sting...
that contains, like many bee and wasp venoms, a cytolytic
Cytolysis
Cytolysis, or osmotic lysis, occurs when a cell bursts due to an osmotic imbalance that has caused excess water to move into the cell. It occurs in a hypotonic environment, where water diffuses into the cell and causes its volume to increase. If the volume of water exceeds the cell membrane's...
peptide
Peptide
Peptides are short polymers of amino acid monomers linked by peptide bonds. They are distinguished from proteins on the basis of size, typically containing less than 50 monomer units. The shortest peptides are dipeptides, consisting of two amino acids joined by a single peptide bond...
(specifically, a mastoparan
Mastoparan
Mastoparan is a peptide toxin from wasp venom. It has the chemical structure Ile-Asn-Leu-Lys-Ala-Leu-Ala-Ala-Leu-Ala-Lys-Lys-Ile-Leu-NH2.The net effect of mastoparan's mode of action depends on cell type, but seemingly always involves exocytosis...
) that can damage tissue by stimulating phospholipase
Phospholipase
A phospholipase is an enzyme that hydrolyzes phospholipids into fatty acids and other lipophilic substances. There are four major classes, termed A, B, C and D, distinguished by the type of reaction which they catalyze:*Phospholipase A...
action, in addition to its own intrinsic phospholipase. Masato Ono, an entomologist
Entomology
Entomology is the scientific study of insects, a branch of arthropodology...
at Tamagawa University
Tamagawa University
is a Japanese university located in Machida, Tokyo, Japan. The university consists of 16 departments in 7 faculties , as well as seven programs leading to a master’s degree and four programs leading to a doctorate degree...
near Tokyo
Tokyo
, ; officially , is one of the 47 prefectures of Japan. Tokyo is the capital of Japan, the center of the Greater Tokyo Area, and the largest metropolitan area of Japan. It is the seat of the Japanese government and the Imperial Palace, and the home of the Japanese Imperial Family...
, described the sensation as feeling "like a hot nail being driven into my leg."
An allergic human stung by the giant hornet may die from an allergic reaction
Allergy
An Allergy is a hypersensitivity disorder of the immune system. Allergic reactions occur when a person's immune system reacts to normally harmless substances in the environment. A substance that causes a reaction is called an allergen. These reactions are acquired, predictable, and rapid...
to the venom, but the venom contains a neurotoxin
Neurotoxin
A neurotoxin is a toxin that acts specifically on nerve cells , usually by interacting with membrane proteins such as ion channels. Some sources are more general, and define the effect of neurotoxins as occurring at nerve tissue...
called mandaratoxin (MDTX), a single-chain polypeptide with a molecular weight of approximately 20,000 u
Atomic mass unit
The unified atomic mass unit or dalton is a unit that is used for indicating mass on an atomic or molecular scale. It is defined as one twelfth of the rest mass of an unbound neutral atom of carbon-12 in its nuclear and electronic ground state, and has a value of...
, which can be lethal even to people who are not allergic if the dose is sufficient. Each year in Japan, the human death toll caused by Asian giant hornet stings exceeds that of all other venomous and non-venomous wild animals combined, including wild bears and venomous snakes.
Predation
The Asian giant hornet is a relentless hunter that preys on other large insectInsect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s, such as bee
Bee
Bees are flying insects closely related to wasps and ants, and are known for their role in pollination and for producing honey and beeswax. Bees are a monophyletic lineage within the superfamily Apoidea, presently classified by the unranked taxon name Anthophila...
s, other hornet species, and mantis
Mantis
Mantis is the common name of any insect in the order Mantodea, also commonly known as praying mantises. The word itself means "prophet" in Latin and Greek...
es.
Honey bee
Honey bees are a subset of bees in the genus Apis, primarily distinguished by the production and storage of honey and the construction of perennial, colonial nests out of wax. Honey bees are the only extant members of the tribe Apini, all in the genus Apis...
hives with the goal of obtaining the honey bee larva
Larva
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...
e. A single scout, sometimes two or three, will cautiously approach the nest, giving off pheromones which will lead the other hornets to the hive's location.
The hornets can devastate a colony of honey bees: a single hornet can kill as many as 40 honey bees per minute thanks to its large mandibles which can quickly strike and decapitate a bee. It takes only a few of these hornets a few hours to exterminate the population of a 30,000-member hive, leaving a trail of severed insect heads and limbs. The European honey bee
European honey bee
The Western honey bee or European honey bee is a species of honey bee. The genus Apis is Latin for "bee", and mellifera comes from Latin melli- "honey" and ferre "to bear"—hence the scientific name means "honey-bearing bee"...
s Apis mellifera have small stings which do little damage to hornets that are five times their size and twenty times their weight. The honey bees make futile solo attacks without mounting a collective defense, and are easily killed individually by the hornets. Once a hive is emptied of all defending bees, the hornets feed on the honey and carry the larvae back to feed to their own larvae. The hornets can fly up to 100 kilometres (62.1 mi) in a single day, at speeds of up to 40 kph
Adult hornets cannot digest solid protein, so the hornets do not eat their prey, but chew them into a paste and feed them to their larvae. The larvae produce a clear liquid, vespa amino acid mixture, which the adults consume; larvae of social Vespidae produce these secretions, the exact amino acid composition varying considerably among species. The passing of nutrition to adult wasps by larvae is widespread in these wasps, and not restricted to the genus Vespa
Hornet
Hornets are the largest eusocial wasps; some species can reach up to in length. The true hornets make up the genus Vespa and are distinguished from other vespines by the width of the vertex , which is proportionally larger in Vespa and by the anteriorly rounded gasters .- Life cycle :In...
.
Native honey bees
Apis cerana japonica
Apis cerana japonica is a subspecies of honeybee native to Japan. It is commonly known as the . This subspecies was determined, through an analysis of mitochondrial DNA, to have originally come from the Korean peninsula. They have been observed moving into urban areas due to lack of natural...
) possesses a collective defense against them.
When a hornet scout locates and approaches a Japanese honey bee hive it will emit specific pheromonal hunting signals. When the honey bees detect these pheromones, a hundred or so will gather near the entrance of the nest and set up a trap, keeping it open apparently to draw the hornet further into the hive or allow it to enter on its own. As the hornet enters the nest, a large mob of about five hundred honey bees surrounds it, completely covering it and preventing it from moving, and the bees begin to quickly vibrate their flight muscles. This has the effect of raising the temperature of the honey bee mass to 46 °C (114.8 °F). In addition, the mob of honey bees raises the level of carbon dioxide (CO2) around the hornet. At that concentration of CO2, the honey bees can tolerate up to 50 °C (122 °F), but the hornet cannot survive the combination of a temperature of 46 °C (114.8 °F) and high carbon dioxide level, so it dies. Often several bees perish along with the intruder, but the death of the hornet scout prevents it from summoning reinforcements which would wipe out the colony.
Beekeepers in Japan attempted to introduce the European honeybee in order to increase productivity. European honeybees, however, have no natural defense against the hornet and the colonies are rapidly destroyed.
Hornet supplement manufacturers
Recently, several companies in Asia and Europe have begun to manufacture dietary supplementDietary supplement
A dietary supplement, also known as food supplement or nutritional supplement, is a preparation intended to supplement the diet and provide nutrients, such as vitamins, minerals, fiber, fatty acids, or amino acids, that may be missing or may not be consumed in sufficient quantities in a person's diet...
s and energy drink
Energy drink
Energy drinks are beverages whose producers advertise that they "boost energy." These advertisements usually do not emphasize energy derived from the sugar and caffeine they contain but rather increased energy release due to a variety of stimulants and vitamins....
s which contain synthetic versions of secretions of the larvae of Vespa mandarinia, which the adult hornets usually consume. The manufacturers of these products make claims that consuming the larval hornet secretions (marketed as "hornet juice") will enhance human endurance because of the effect it has on adult hornets' performance. Because these products are marketed as dietary supplement rather than pharmaceuticals, they do not have to support their claims. Some studies have suggested that the vespa amino acid mixture itself may influence animal performance in minor ways.